A mollusc discovered in 1950s is

Options

A. Nautilus
B. Chiton
C. Neopilina
D. Pelecypoda.

Answer

To answer the question "A mollusc discovered in 1950s is," we can follow these steps:

### Step 1: Understand the Phylum Mollusca
Mollusca is one of the largest marine phyla, which includes a diverse range of organisms such as gastropods (snails and slugs), bivalves (clams and oysters), and cephalopods (squids and octopuses).

**Hint:** Remember that Mollusca includes various groups, and knowing these groups can help narrow down your options.

### Step 2: Identify the Options
The options given are:
- Nautilus
- Cheton
- Neopilina
- Pallasipoda

**Hint:** Look for any historical context or notable discoveries related to these organisms.

### Step 3: Research the Discovery Timeline
Among the options, we need to identify which mollusc was discovered in the 1950s. Neopilina is known to have been discovered around this time.

**Hint:** Focus on the specific years or decades when these organisms were first discovered.

### Step 4: Understand the Significance of Neopilina
Neopilina is significant because its discovery led to the classification of a new class within Mollusca called Monoplacophora. It also serves as a connecting link between the annelids and mollusks.

**Hint:** Consider the implications of a discovery on classification and evolutionary relationships.

### Step 5: Conclude the Answer
Based on the information gathered, the correct answer to the question is Neopilina.

**Final Answer:** The mollusc discovered in the 1950s is Neopilina (Option C).

---